They are categorized as perennial or seasonal according to the time of onset. The main cause of seasonal allergies in China is Artemisia pollen, followed by ragweed pollen. Pollen that can cause sensitization must have antigenic properties; pollen without antigenic properties does not cause hay fever. Every year at the beginning of autumn, autumn high, a large number of artemisia pollen in the air, these patients tend to develop at this time. Clinical performance is complex and variable, allergic rhinitis is mainly nasal congestion, sneezing, a lot of watery nasal discharge, nostril itching, or even coughing and wheezing, can also be manifested as urticaria and other skin diseases. If the secondary infection course can be delayed until December. Some people can be transformed into perennial after two years of illness, and will also develop when encountering hot and cold or stimulating odors. Prevention and treatment: First, avoid contact with allergens. Second, desensitization treatment. That is, a small amount of multiple times gradually increase the amount of allergens (such as pollen) injection, until the patient’s body to produce antibodies. The treatment time is usually 3-5 years. Third, drug treatment. In the past 10 years, effective and safe once-daily medications have taken the lead in treatment, especially for seasonal allergic rhinitis and urticaria. Currently, the main drugs used in the treatment of seasonal allergic rhinitis are antihistamines, anti-allergic drugs (the drug of choice), topical nasal steroids (first-line drugs), mast cell membrane stabilizers (no side effects, for pediatrics, mild patients) and decongestants and anticholinergics. Leukotriene antagonists (newer drugs) are also effective in relieving nasal congestion, runny nose and eye symptoms. They may be used in combination with other drugs.